Mechanism for sequential contact switches



May 10, 1949. E. A. MILLER 2,469,976

MECHANISM FOR SEQUENTIAL CONTACT SWITCHES Filed April 23, 1947 EDWIN AUGUET MMEW Patented May 10, 1949 MECHANISM FOR SEQUENTIAL CONTACT SWITCHES Edwin August Miller, Fairfield, Conn. Application April 23, 1947, Serial No. 743,265

(Cl. 20G-.67)

4 Claims. l

This invention relates to mechanism for snapacting switches and more particularly to such mechanism providing sequential contacts upon a full operation of an actuator.

The objects of the invention are to provide such mechanism that will have high contact pressure for a small size switch; to provide a self-wiping contact action minimizing contact Welding; to provide contact action in sequence increasing switch potentialities as a control device; to provide a. compact switch having sequential contact action for use where weight and space are given factors; and to provide for a sequential action switch adjusting means for regulating varied sequential contact action.

The applicant is aware that the prior art discloses switch Astructures embodying sequential contact action with respect to a floating switch blade movable between pairs of xed stops of which the stops of one pair are variably spaced, one from the other, and differently from that of the other pair, or embodying an actuator carrying spring arms, each 'of which is connected to a compression arm, said arms being of diiierent lengths.

The applicant is also aware thatit is old to provide a compression arm of a cantilever type with a U-shaped loop portion, such arm at one extremity being supported by a rigid base, and also it is old to provide a separate looped spring for a connection between an actuator and a part to be acted upon.

It will be understood, however, as the novel structure ofthe mechanism is herein disclosed, that the prior art does not anticipate the features of this invention.

Referring to the accompanying drawing, the Figure 1 illustrates the mechanism of the device in unoperated position, a front cover of the insulation casing being removed; Figure 2 is a similar view of the mechanism in partially operated position; Figure 3 is another view of said mechanism maintained in fully operated position; Figure 4 is a plan view of said mechanism, the casing including a cover but a top casing Wall is removed; and Figure 5 is a detail illustrating a slight modification with respect to the blade member.

With more particular reference to the accompanying drawing, the numeral I designates portions of the insulation casing, and 2 the front cover thereof. The casing cavity 3 is iixedly provided with two pairs of projecting stops 4-5 and 6-1, the stops of each pair being relatively spaced, one from the other, in alignment at Ollposite ends of the cavity 3. Positioned within the cavity 3, and bodily movable between stops 5-1 and 4 6, is the switch blade 8 having therethrough the elongated opening 9 and carrying at opposite extremities of the blade 8 the contacts I0 and II on the upper side thereof and contacts I2-I3 upon the lower side, the contacts IU-II being respectively engageable with the Xed contacts or stops 4 6 and the contacts I2-I3 being respectively engageable with the fixed contacts or stops 5-I.

Non-rotatably supported by the base I within the passage I4, communicating with the cavity 3, is the push actuator I5 transversely extending, as at 23A, through the opening 9 oi' the blade l. Opposite lower sides of the actuator I5 are provided with a series of axially spaced notches I6-I1.

A pair of relatively opposing compression arms I8--I9 is positioned Within said opening 9 of the blade 8, each arm having an end carried by an extremity of the blade 8, and an opposite end engaged within a notch IIB or I'I of the actuator I5. One of said compression arms Iii-I9 is provided with a U-shaped looped portion 20 adjacent its notch engagement.

The actuator I5 is shown in the Figures 1 and 2 with a coil spring 22 to insure return movement of the actuator, but such spring may be omitted if both positions of the actuator I5 are maintained and the lower end of the actuator 23 being adapted for a manual pushing operation.

The normal position of the snap-acting mechanism, illustrated by the Figure 1, may b'e operated a first step by means of a part-way downward pressure of the push actuator I E. This moves the mechanism to the position illustrated by the Figure 2. Such moved position shows the movable contact I0 in engagement with the stop 4. the movable contact I3 not having Ibroken contact with the stop 1, by reason of the greater force exercised by the compression arm I8, as compared with'that of the looped arm I3, the action of the looped arm I9 is retarded until a full operation of the actuator I5. Upon a full operation of the actuator I5 the contact with the stop 1 is broken and the contact II is moved into engagement with the stop 8, the switch blade 8 bridging the stops 4-6, as illustrated by the Figure 3. The part-way and full operations of the mechanism enables the employment of stops 4 and 6, each included in separate electric circuits and thus dividing the full operation of the mechanism into two distinct means of device control.

` lengaging the contact I with vthe stop II.

' compression arm I8 is The movements of the contacts I0, II, I2 and I3 carried by the blade 8 are all snap-acting. While the Figure l shows the contact I2 and I3 maintained in engagement with the stops -1, respectively, the contacts I0 and II may likewise be maintained in engagement with the stops 4 and 6 by omitting the coil spring 22. The actuator I5 may then be operated both ways by manually pushing it in either direction.

As the actuator I5 is partially operated downwardly, both notch-engaged ends of the compression arms I8-I19, in their respective notches of the series |8--I1, are carried thereby in undercentering relation to the blade 8 whereby the compression arm I8 of greater compressional force operates its end of the blade 8 upwardl further Operated actuator I5 carries the notchengaged ends farther downwardly whereby the arm: I9 operates the blade 8 to lift its end of the blade 8 to engage the contact II with the stop S.

During the operation above explained, and also the operation of the mechanism in reverse thereor, the snap-acting movement of oppositely carriad contacts occur in sequence and all engagements thus made are surface wiping contacts, thereby minimizing the possibility of Contact welding.

The :wiping engagements by the movable contants tti, ii, i2 and i3 are provided upon the downwardly movement of the actuator i5 b y the greater compressional force lexercised by the arm liti, as compared with that of the weaker arm iii, the arm i8 slightly shifting the blade 8 longitudinally one way but, upon the spring 22 or other return of theactuator i5, the release of the arm it from a cramped position, occurring with a full operation of the actuator i5 relative to the blade 8, shifts the blade B longitudinally the other way.

in the snap-acting switch mechanism above disclosed, there is assured a good contact pressure in all sequential positions of the movable contacts in engagement with stops.

The compression arm I8 being above referred to as the arm having the greater compression force, and the arm I9 as having the weaker force of the two arms, a more denite explanation concerning 'the reason for the difference in com- 'pressional force of these two arms I8 and I9 might be better understood as follows:

Before assembling the parts of the mechanism, the compression arm I8v has the tendency to lie substantially in the plane of the blade 8, as illustrated by the Figure 5. Upon assembling, the bent slightly upwardly with its free end held infa .notch-engagement with the actuator I5 above the blade 8, as illustrated by the Figure 1, and thus maintained in readiness to be snap-actingly moved downwardly as the actuator I5 is operated to carry the notch-engaged action so distorts the blade 8 as to move the contact III with a snap-action into engagement with the stop 4, asillustrated by the Figure 2. In other words,the compression arm I8 having the natural tendency to lie substantially in the plane of the blade 8, as illustrated by the Figure 5,

,y responds alike to be positioned above or below the end of the am I8 to -below the blade 8. This of the compression arm I9, that portion 2,0, before and following the assembly of the mechanism, lies below the blade 8 although its notchengaged end is held above the blade 8, as illustrated by the Figure 1. Therefore, upon the operation of the downwardly pressed actuator I5, it is the compression arm I8 that responds more readily for a snap-acting movement from an over-centered to an under-centered position relative to the blade 8, the snap-action of the arm I9 being delayed until a full operation of the actuator l5 when the biased or looped portion 20 of the compression arm I9 becomes cramped and causing the remaining portion of the arm I9 to be under-centered with relation to the blade 8 and to so distort the blade 8 as tomove with a snap-action the contact Il into engagement with the stop 6.

However, with a reversed movement of the switch mechanism, by means of the spring 22, or manual pressure against the lower end 23 of the actuator l5, the contact II in engagement with the stop 6 is the first to break engagement because of the forceful release of the cramped condition of the biased or looped portion 20 of the compression arm I9 giving the arm I9 in- 'i9 is moved to over-centered position with respect to the blade thereby being distorted and moving with a snap-action the contact IS--into engagement with the stop l. As the spring or manual pressure continues to move the actuator l5 upwardly, the compression arm I8, now in sequence, vis over-centered with respect to the blade t whereby the blade 8 being distorted moves and engages with a snap-action the contact i2 with the stop 5, said blade 8 bridging the stops 5 and While the structure of the mechanism, as herein shown and specified, provides for a definite manner of sequential action of movable contacts Iii, Il, I2 and I3, it is to be understood that, by readjusting the notch-engaged ends of either or both compression arms I8 or IS in engagement with any of the series of notches I8-Il,

a variance of such sequential contact action may be accomplished and is herein intended to be included as within the scope of this invention.

The modified structure of a detail of the mechanism, illustrated by the Figure 5, shows a compression arm ISA having a U-shaped biased or looped portion 20A secured with, and upon, the top surface of an extremity of the switch blade 8A by means of a rivet 2l the head of which serves as a contact IIA and the opposite end of said rivet 2l as a contact ISA carried by the blade 8A. If desired, both compression arms I8 and IBA likewise may be provided with such attached compression arms.

I claim:

1. A snap-acting. switch mechanism comprising a base; pairs of upper and lower fixed stops provided b y said base; a contact-carrying switch blade bodily movable between said upperand lower stops and having an opening therethrough; a non-rotatable push actuator slidingly supported by said base and extending transversely to, and movable within, said opening; notches with which the actuator is provided upon opposite sides and lower end thereof; a pair of relatively opposing compression arms within said opening. each arm having an end carried by an 2,4eaove extremity of said blade, and an opposite end engaged within one of said notches; and a looped end portion of one of said compression arms adjacent its notch engagement, said looped portion depending from said arm below said blade; a lowered position of said looped portion resulting from a partial actuator operation moving with a snap-action the other compression arm from an over-center to an under-center relation to said blade, and also in a contact engagement of said blade with one of said upper stops; a cramped position of said looped portion resulting, upon a full operation of said actuator, in a snap-acting under-centering movement of the looped compression arm with respect to said blade; and a sequentia1 contact engagement of said blade with the other of said upper stops, said engagement being in sequence with respect to the contact engagement of said blade with an upper stop.

2. A snap-acting switch mechanism, as set forth in claim 1, said mechanism including a reversed movement thereof upon the operation of said actuator manually or by a return spring; a released position of said cramped looped portion upon the partial return of said actuator resulting in a snap-acting over-centering movement of the looped compression arm with respect to said blade, and also in breaking and making contact movement from an upper to a vlower of said stops; and a fully returned position of said actuator resulting in a snap-acting over-centering movement of the other of said compression arms with respect to said blade, and also in a breaking and making contact engagement from an upper 35 3. A snap-acting switch mechanism, as set 40 forth in claims 1 and 2, said mechanism including surface-wiping contact engagements with Y said stops upon a longitudinally shift-movement of said blade resulting from the greater force alternately exercised by said compression arms 45 2'429812 Vupon the operation of said actuator by manual or spring return means.

4. A snap-acting switch mechanism comprising a base; pairs of upper and lower-xed stops provided by said base; a contact-carrying switch blade bodily movable between said upper and lower stops and having an opening therethrough; a non-rotatable push actuator slidingly supported by said base and extending transversely to, and movable within, said opening; notches with which the actuator is provided upon opposite sides and lower end thereof; a pair of relatively opposing compression arms within said opening, each arm having yan end carried by an extremity of said blade, and an opposite end engaged within one of said notches; and a looped portion on one of said compression arms, said looped portion depending from said arm; a lowered position of said looped portion resulting from a partial actuator operation moving with -a snap-action the other compression arm from an over-center to an under-center relation to said blade, and also in a contact engagement of said blade with one of said upper stops; an increased compressed position of said looped portion resulting, upon a full operation of said actuator,

` in a snap-acting under-centering movement of said engagement being in sequence with respect to the contact engagement of said blade with an upper stop.

EDWIN AUGUST MILLER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,332,911 Hausler Oct. 26, 1943 2,360,128 Hausler Oct. 10, 1944 2,400,754 Hausler May 12, 1946 Hausler Oct. 28, 1947 

